Transport In Xylem And Phloem

This section discusses the structure and function of xylem and phloem in plants, focusing on their roles in transporting water, minerals, and organic compounds.

Transport In The Xylem

The xylem is crucial for water and mineral transport in plants, using various cellular structures and mechanisms.

Function

The section highlights the key functions and structures of the xylem and phloem, detailing their roles in plant transport systems.

Structure

This section discusses the structure of xylem and phloem in plants, highlighting their roles in transporting water, minerals, and organic compounds.

Xylem Vessels

Xylem vessels are specialized structures in plants responsible for transporting water and dissolved minerals from roots to leaves.

Tracheids

Tracheids are elongated, lignified cells in the xylem that facilitate water transport in plants.

Fibres

Fibres in plants provide structural support, vital for their growth and stability.

Parenchyma

Parenchyma cells are living tissues in plants that play key roles in storage and lateral transport of nutrients.

Mechanism Of Water Transport

Water transport in plants occurs mainly through xylem, utilizing processes like transpiration, cohesion, and root pressure.

Transpiration

Transpiration is the process by which water is transported from the roots to the leaves of plants through the xylem, driven by evaporation.

Cohesion And Adhesion

This section explains the concepts of cohesion and adhesion as they relate to water transport in plants, highlighting their critical roles in the movement of water through xylem vessels.

Root Pressure

Root pressure is the positive pressure generated in the root xylem by the active transport of ions, which helps push water upward in plants.

Transport In The Phloem

The phloem is essential for transporting organic compounds, primarily sucrose, from sources to sinks in plants.

Function

This section describes the functions, structures, and mechanisms of transport in xylem and phloem.

Structure

This section discusses the structure of xylem and phloem, highlighting their roles in transporting water, minerals, and organic compounds in plants.

Sieve Tube Elements

Sieve tube elements are essential living cells in the phloem that facilitate the transport of organic compounds in plants.

Companion Cells

Companion cells are specialized plant cells that support the function of sieve tube elements in the phloem, aiding in the transport of organic compounds.

Mechanism Of Translocation

The mechanism of translocation in plants describes how organic compounds, mainly sucrose, are transported from sources to sinks through the phloem.

Phloem Loading

Phloem loading is the process of actively transporting sucrose into phloem sieve tubes, which is crucial for distributing food throughout the plant.

Pressure Flow

Pressure flow is the mechanism by which phloem transports organic compounds in plants, particularly through differential turgor pressure.

Plant Growth And Hormones

This section discusses meristems, plant hormones, and tropism, highlighting their roles in plant growth.

Meristems And Growth

This section covers the types of meristems and their role in plant growth, as well as the primary plant hormones that regulate growth processes.

Meristems

Meristems are regions of undifferentiated plant cells capable of continuous division, contributing to both primary and secondary growth.

Apical Meristems

Apical meristems are responsible for primary growth in plants, found at the tips of roots and shoots.

Lateral Meristems

Lateral meristems are specialized tissues in plants responsible for secondary growth, providing thickness and increased vascular capability.

Plant Hormones

Plant hormones regulate growth, development, and responses to environmental stimuli.

Auxins (E.g., Iaa)

Auxins are plant hormones that regulate growth by promoting cell elongation and influencing various growth responses.

Gibberellins

Gibberellins are plant hormones that play a crucial role in stimulating stem elongation, seed germination, and flowering.

Cytokinins

Cytokinins are plant hormones that promote cell division and differentiation, impacting growth and development.

Abscisic Acid (Aba)

Abscisic acid (ABA) is a plant hormone that plays a crucial role in regulating water stress responses and maintaining seed dormancy.

Ethylene

Ethylene is a plant hormone that plays a crucial role in promoting fruit ripening and leaf abscission.

Tropisms

Tropisms are growth responses of plants to environmental stimuli, primarily influenced by hormones like auxins.

Phototropism

Phototropism is the growth response of plants to light, primarily regulated by the distribution of auxins.

Gravitropism

Gravitropism is the directional growth of plant parts in response to gravity, with roots exhibiting positive gravitropism and shoots showing negative gravitropism.

Micropropagation

Micropropagation is a tissue culture technique used to produce large numbers of identical plants.

Reproduction In Plants

This section covers the structure and function of flowers, the processes of pollination and fertilization, seed dispersal, and the concept of photoperiodism in relation to flowering.

Flower Structure And Function

Flowers consist of various parts that play crucial roles in plant reproduction, including mechanisms for pollination and seed dispersal.

Sepals

Sepals are the protective structures of a flower bud, helping to guard the developing flower.

Petals

Petals play a crucial role in attracting pollinators to flowers, facilitating reproduction in plants.

Stamens

The stamen is the male reproductive organ of flowering plants, made up of anthers that produce pollen and filaments that support them.

Carpels (Pistils)

Carpels are the female reproductive organs in flowering plants, consisting of the stigma, style, and ovary, each playing a crucial role in reproduction and the production of seeds.

Pollination, Fertilization, And Seed Dispersal

This section covers the processes of pollination, fertilization, and seed dispersal in plants, highlighting their ecological importance.

Pollination

Pollination is the transfer of pollen from the male anthers to the female stigma, essential for plant fertilization.

Fertilization

This section covers the process of fertilization in plants, detailing the mechanisms involved from pollination to zygote formation.

Seed Dispersal

Seed dispersal involves the spreading of seeds away from the parent plant to reduce competition for resources.

Photoperiodism And Flowering

This section discusses how plants respond to light duration, influencing flowering through photoperiodism and the role of phytochromes.

Photoperiodism

Photoperiodism is the reaction of plants to the lengths of light and dark periods, influencing their flowering patterns.

Short-Day Plants

Short-day plants flower in response to longer periods of darkness, triggering their reproductive cycle.

Long-Day Plants

Long-day plants flower when the duration of light surpasses a critical threshold, primarily influenced by photoperiodism and phytochrome activity.

Phytochromes

Phytochromes are light-sensitive proteins that play a crucial role in regulating flowering time in response to changes in light quality.